Mine, too... but...
When I first got my Crossfire, I was concerned about how it pulled to one side or the other - never consistantly left or right - when breaking from a SLOW speed. Steering issues? Alignment? Brakes?
I thought it was a problem, but after posting the same question as yours (maybe six or seven months ago) and reading the responses, I felt better about it, and I'm just used to it now.
I do NOT think it's a mechanical problem, and it's just a quirk of the Crossfire's tire/wheelbase combination as indicated by the sage posters above.